<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>$Title$</title>
    <script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script>
    <script>
        function a() {
            $.post({
                url: "${pageContext.request.contextPath}/a1",
                data:{"name":$("#username").val()},
                success:function (res) {
                    alert(res);
                }
            });
        }
    </script>
</head>
<body>
用户名:<input type="text" onblur="a()" id="username">
</body>

</html>
